Heat exchanger system used in steel making

ABSTRACT

The invention is a heat exchanger system suitable for iron making furnaces and their supporting exhaust and cooling system. The heat exchanger has at least one panel of sinuously winding piping having an inlet and an outlet, an input manifold in fluid communication with the inlet of the at least one panel, an output manifold in fluid communication with the outlet of the panel, a cooling fluid flowing through the piping, and a stream of hot exhaust gasses flowing over the piping. In application, the heat exchanger system has at least one panel that is mounted to an interior side of a wall, and is in fluid communication with the output and the input manifolds that are on an exterior side of the wall. The wall typically is a wall of a steel making furnace, a furnace roof, a smoke ring exhaust port, a straight section of an exhaust duct, and a curved section of an exhaust duct. It is anticipated that the heat exchanger has other applications, such as cooling exhaust gasses from converting plants, paper manufacturing plants, coal and gas fired electrical power generation plants, and other exhaust gas generators, where the gasses are cooled for the purpose of capturing one or more components of the gas, where capture is effected by condensation, by carbon bed absorption, or by filtration. The heat exchanger system is preferably fabricated using an aluminum bronze alloy. Aluminum bronze alloys have been found to have a higher than expected thermal conductivity, resistance to etching by the stream of hot gasses, and good resistance to oxidation. The operational life of the heat exchanger is extended. Corrosion and erosion of the heat exchanger and related components is reduced, when they are fabricated with aluminum bronze alloy.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of patent applicationSer. No. 10/238,971 filed on Sep. 11, 2002, which claims the benefit ofU.S. Provisional Application No. 60/323,265, filed Sep. 19, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to apparatus for metallurgicalprocessing, particularly steel and iron making. More particularly, theinvention relates to a heat exchanger system used in a metallurgicalfurnace and its support components, wherein the heat exchanger systemcomprises aluminum bronze alloy piping. The heat exchanger systemincludes piping mounted to the furnace wall, the furnace roof, and tothe off-gas system, where the off-gas system comprises off-gas ductingand a smoke ring. The heat exchanger system provides cooling, and thealuminum bronze alloy piping extends the operational life of thefurnace.

BACKGROUND OF THE INVENTION

[0003] Today, steel is made by melting and refining iron and steel scrapin a metallurgical furnace. Typically, the furnace is an electric arcfurnace (EAF) or basic oxygen furnace (BOF). With respect to the EAFfurnaces, the furnace is considered by those skilled in the art of steelproduction to be the single most critical apparatus in a steel mill orfoundry. Consequently, it is of vital importance that each EAF remainoperational for as long as possible.

[0004] Structural damage caused during the charging process affects theoperation of an EAF. Since scrap has a lower effective density thanmolten steel, the EAF must have sufficient volume to accommodate thescrap and still produce the desired amount of steel. As the scrap meltsit forms a hot metal bath in the hearth or smelting area in the lowerportion of the furnace. As the volume of steel in the furnace isreduced, however, the free volume in the EAF increases. The portion ofthe furnace above the hearth or smelting area must be protected againstthe high internal temperatures of the furnace. The vessel wall, cover orroof, duct work, and off-gas chamber are particularly at risk frommassive thermal, chemical, and mechanical stresses caused by chargingand melting the scrap and refining the resulting steel. Such stressesgreatly limit the operational life of the furnace.

[0005] Historically, the EAF was generally designed and fabricated as awelded steel structure which was protected against the high temperaturesof the furnace by a refractory lining. In the late 1970's and early1980's, the steel industry began to combat operational stresses byreplacing expensive refractory brick with water cooled roof panels, andwater cooled sidewall panels located in portions of the furnace vesselabove the smelting area. Water cooled components have also been used toline furnace duct work in the off-gas systems. Existing water cooledcomponents are made with various grades and types of plates and pipes.An example of a cooling system is disclosed in U.S. Pat. No. 4,207,060which uses a series of cooling coils. Generally, the coils are formedfrom adjacent pipe sections with a curved end cap, which forms a pathfor a liquid coolant flowing through the coils. This coolant is forcedthrough the pipes under pressure to maximize heat transfer. Current artuses carbon steel and stainless steel to form the plates and pipes.

[0006] In addition, today's modern EAF furnaces require pollutioncontrol to capture the off-gasses that are created during the process ofmaking steel. Fumes from the furnace are generally captured in two ways.Both of these processes are employed during the operation of thefurnace. One form of capturing the off-gasses is through a furnacecanopy. The canopy is similar to an oven hood. It is part of thebuilding and catches gasses during charging and tapping. The canopy alsocatches fugitive emissions that may occur during the melting process.Typically, the canopy is connected to a bag house through a non-watercooled duct. The bag house is comprised of filter bags and several fansthat push or pull air and off-gasses through the filter bags to cleansethe air and gas of any pollutants.

[0007] The second manner of capturing the off-gas emissions is throughthe primary furnace line. During the melting cycle of the furnace, adamper closes the duct to the canopy and opens a duct in the primaryline. This is a direct connection to the furnace and is the main methodof capturing the emissions of the furnace. The primary line is also usedto control the pressure of the furnace. This line is made up of watercooled duct work as temperatures can reach 4,000° F. and then drop toambient in a few seconds. The gas streams generally include variouschemical elements, including hydrochloric and sulfuric acids. There arealso many solids and sand type particles. The velocity of the gas streamcan be upwards of 150 ft./sec. These gasses will be directed to the mainbag house for cleansing, as hereinabove described.

[0008] The above-described environments place a high level of strain onthe water cooled components of the primary ducts of the EAF furnace. Thevariable temperature ranges cause expansion and contraction issues inthe components which lead to material failure. Moreover, the dustparticles continuously erode the surface of the pipe in a manner similarto sand blasting. Acids flowing through the system also increase theattack on the material, additionally decreasing the overall lifespan.

[0009] Concerning BOF systems, improvements in BOF refractories andsteelmaking methods have extended operational life. However, theoperational life is limited by, and related to, the durability of theoff-gas system components, particularly the duct work of the off-gassystem. With respect to this system, when failure occurs, the systemmust be shut down for repair to prevent the release of gas and fumesinto the atmosphere. Current failure rates cause an average furnace shutdown of 14 days. As with EAF type furnaces, components have historicallybeen comprised of water cooled carbon steel, or stainless steel typepanels.

[0010] Using water cooled components in either EAF or BOF type furnaceshas reduced refractory costs, and has also enabled steelmakers tooperate each furnace for a greater number of heats than was possiblewithout such components. Furthermore, water cooled equipment has enabledthe furnaces to operate at increased levels of power. Consequently,production has increased and furnace availability has becomeincreasingly important. Notwithstanding the benefits of water cooledcomponents, these components have consistent problems with wear,corrosion, erosion, and other damage. Another problem associated withfurnaces is that as available scrap to the furnace has been reduced inquality, more acidic gasses are created. This is generally the result ofa higher concentration of plastics in the scrap. These acidic gassesmust be evacuated from the furnace to a gas cleaning system so that theymay be released into the atmosphere. These gasses are directed to theoff-gas chamber, or gas cleaning system, by a plurality of fume ductscontaining water cooled pipes. However, over time, the water cooledcomponents and the fume ducts give way to acid attack, metal fatigue, orerosion. Certain materials (i.e., carbon steel and stainless steel) havebeen utilized in an attempt to resolve the issue of the acid attack.More water and higher water temperatures have been used with carbonsteel in an attempt to reduce water concentration in the scrap, andreduce the risk of acidic dust sticking to the side walls of a furnace.The use of such carbon steel in this manner has proven to beineffective.

[0011] Stainless steel has also been tried in various grades. Whilestainless steel is less prone to acidic attack, it does not possess theheat transfer characteristics of carbon steel. The results obtained werean elevated off-gas temperature, and built up mechanical stresses thatcaused certain parts to fracture and break apart.

[0012] Critical breakdowns of one or more of the components commonlyoccurs in existing systems due to the problems set forth above. Whensuch a breakdown occurs, the furnace must be taken out of production forunscheduled maintenance to repair the damaged water cooled components.Since molten steel is not being produced by the steel mill duringdowntime, opportunity losses of as much as five thousand dollars perminute for the production of certain types of steel can occur. Inaddition to decreased production, unscheduled interruptionssignificantly increase operating and maintenance expenses.

[0013] In addition to the water cooled components, corrosion and erosionis becoming a serious problem with the fume ducts and off gas systems ofboth EAF and BOF systems. Damage to these areas of the furnace resultsin loss of productivity and additional maintenance costs for milloperators. Further, water leaks increase the humidity in the off-gasses,and reduce the efficiency of the bag house as the bags become wet andclogged. The accelerated erosion of these areas used to dischargefurnace off-gasses is due to elevated temperatures and gas velocitiescaused by increased energy in the furnace. The higher gas velocities aredue to greater efforts to evacuate all of the fumes for compliance withair emissions regulations. The corrosion of the fume ducts is due toacid formulation/attack on the inside of the duct caused by the meetingsof various materials in the furnaces. The prior art currently teaches ofthe use of fume duct equipment and other components made of carbon steelor stainless steel. For the same reasons as stated above, thesematerials have proven to provide unsatisfactory and inefficient results.

[0014] A need, therefore, exists for an improved water cooled furnacepanel system and method for making steel. Specifically, a need existsfor an improved method and system wherein water cooled components andfume ducts remain operable longer than existing comparable components.

SUMMARY OF THE INVENTION

[0015] The present invention is a heat exchanger system suitable foriron making furnaces and their supporting exhaust and cooling system.The heat exchanger has at least one panel of sinuously winding pipinghaving an inlet and an outlet, an input manifold in fluid communicationwith the inlet of the at least one panel, an output manifold in fluidcommunication with the outlet of the panel, a cooling fluid flowingthrough the piping, and a stream of hot exhaust gasses flowing over thepiping. In this disclosure, the terms tubing, pipes, and piping aresynonymous, and used interchangeably. The sinuously winding piping issubstantially an assemblage of sectional lengths of connected tubes orpipes mounted side-by-side. The connected tubes are secured to eachother with a linkage thereby forming a solid panel, where the panel hasstructural integrity. The linkages add rigidity to the system, andestablish the overall planarity and partially, or all of, the curvatureof the panel. For instance, by adjusting the side-by-side relationshipof the connected tubes, such that they are slightly displaced severaldegrees from zero, the cumulative effect produces a solid panel that hascurvature, instead of being flat. In most applications, the heatexchanger system has at least one panel mounted to an interior side of awall, where the panel is in fluid communication with the output and theinput manifolds that are on an exterior side of the wall. The walltypically is a wall of a steel making furnace, a furnace roof, a smokering exhaust port, a straight section of an exhaust duct, and a curvedsection of an exhaust duct. In many of the identified applications, thewall is curved. For instance, a furnace exhaust duct is typicallyellipsoidal or round, depending on the design parameters. The interiorside of the exhaust duct wall can have one or a plurality of panels,where the panels have a curvature that is comparable to the curvature ofthe duct. The plurality of panels is each individually supplied coolingliquid from the output manifold, which encircles the exterior side ofthe exhaust duct. The plurality of panels returns the cooling liquid tothe output manifold, which encircles the exterior side of the exhaustduct.

[0016] The heat exchanger system can be used to collect and cool slagformed on the furnace wall. The heat exchanger reduces the formation ofstress risers. Preferably, the tubes have at least one spline that is anelongate ridge. The tubes are preferably fabricated into panels wherethe tubes have an orientation that is substantially horizontal with themolten material in the furnace. Typically, the furnace walls are curved,and the tubes are also curved so as to follow the curvature of thefurnace wall (a.k.a., shell). One tube can track around the entireinside circumference of the furnace wall, however, a more effective,uniform temperature configuration is to break the circumference downinto arcs, and utilize sectional lengths of piping that are seriallyconnected with adjacent connected tubes. An assemblage of sectionallengths of connected tubes mounted side-by-side forms a panel. Theplurality of panels are individually supplied cooling liquid from theoutput manifold, which is on the exterior side of the furnace wall. Theplurality of panels returns the cooling liquid to the output manifold,which is on the exterior side of the furnace wall. In a modifiedversion, the heat exchanger system can have more than one inlet, andmore than one outlet within the assemblage of connected tubes, where theassemblage is curved to follow the contour of the interior side of thefurnace wall. The assemblage can be configured such that a firstassemblage of connected pipes loops inside a second assemblage ofconnected pipes.

[0017] The heat exchanger system can be further comprised of a baseplate to which the sinuously winding piping is attached. Air flow overand around the piping of this system is not as complete as one where thepiping is secured merely by linkages, however, great shear strength canbe achieved, and this system is particularly suitable where air borne orsplashed solids (slag) will collect, or where there is a lot ofvibration. The employment of a base plate is well suited forapplications where the heat exchanger system is used to collect slag.

[0018] The heat exchanger system can be further comprised of a frontplate as well as the base plate, wherein the sinuously winding piping issandwiched between the base plate and the front plate. The front plateis preferably fabricated out of aluminum bronze alloys, where thealuminum bronze alloy is selected for its high coefficient of thermalconductivity, especially at the higher operating temperatures. Theutilization of two plates enables the sinuously winding piping to bereplaced with baffles or weirs, which act to direct the cooling fluid toflow in a manner similar to the pipes. The fluid winds sinuously througha channel defined by the baffles between the front plate and the baseplate. The baffles are substantially perpendicular elongate plates. In apreferred construction, a longitudinal edge of the baffle is welded to abackside of the front plate, and the base plate is attached to anopposing longitudinal edge of the baffle. As previously enumerated, thecombination of plates and baffles affects a sinuously winding channel,where the channel is substantially comparable to a fabricated tube. Afront side of the front plate is exposed to the hot exhaust gasses.

[0019] The heat exchanger system can alternatively be comprised of afront plate and a base plate, wherein piping is fitted with spraynozzles that direct a spray of the cooling fluid on a backside of thefront plate. The front plate is preferably fabricated out of aluminumbronze alloy, where the aluminum bronze alloy is selected for itsresistance to oxidation as well as its high coefficient of thermalconductivity. The base plate serves principally as a mounting platformfor the pipes fitted with nozzles. The front plate is offset from thenozzles, which are directed toward the backside of the front plate. Thefront side of the aluminum bronze plate is exposed to the heat, and thespray is collected and returned via the output manifolds. The inputmanifolds provide the pressurized cooling fluid. The cooling fluid ispreferably water because of it low cost and high heat capacity. Thenozzles disperse the cooling fluid as a spray pattern and less piping isrequired, thereby reducing the need that the pipes be sinuously winding.The heat exchanger system using nozzles is configured such that drainageis always toward the bottom of the panel so as to prevent a buildup ofcooling fluid from obstructing the nozzles.

[0020] The heat exchanger system is configured such that cumulatively,the total number of panels is sufficient to cover an area that cools theexhaust gasses to a desired temperature. In the case of exhaust gassesfrom an electric arc furnace the exit temperature of the gasses isaround 4,000° F.-5,000° F. Theses gasses are filtered at a bag house toremove vaporized metals, such as zinc, and certain volatile ashes. Baghouses operate at about 200° F.-350° F. and, therefore, incoming exhaustgasses must be cooled accordingly. The panels are fabricated to becurved or planar, thereby producing the needed surface area for a givencooling requirement.

[0021] It is anticipated that the present heat exchanger system can beused in combination with other heat transfer equipment, such ascondensers, shell and tube-type exchangers, finned exchangers,plate-and-frame-heat exchangers, and forced-draft air-cooled exchangers.

[0022] It is further anticipated that the heat exchanger has otherapplications, such as cooling exhaust gasses from converting plants,paper manufacturing plants, coal and gas fired electrical powergeneration plants, and other exhaust gas generators, where the gassesare cooled for the purpose of capturing one or more components of thegas, where capture is effected by condensation, by carbon bedabsorption, or by filtration. The heat exchanger system is preferablyfabricated using an aluminum bronze alloy. Aluminum bronze alloys havebeen found to have a higher than expected thermal conductivity,resistance to etching by the stream of hot gasses (modulus ofelasticity), and good resistance to oxidation. Thus, the operationallife of the heat exchanger is extended. Corrosion and erosion of theheat exchanger and related components is reduced, when they arefabricated with aluminum bronze.

OBJECTS OF THE INVENTION

[0023] A first object of the present invention is to provide a heatexchanger system constructed of aluminum bronze alloys, where aluminumbronze alloys have been found to have a higher than expected thermalconductivity, resistance to etching by the stream of hot gasses, andgood resistance to oxidation.

[0024] A second object of the present invention is to provide a heatexchanger system wherein the operational life of the heat exchanger isextended, as corrosion and erosion of the heat exchanger and relatedcomponents is reduced when they are fabricated with aluminum bronzealloy.

[0025] A third object of the present invention is to provide a heatexchanger system, wherein the system is adaptable for cooling exhaustgasses emanating from a steel making furnace, wherein the heat exchangersystem can be fitted to the walls of the furnace, a furnace roof, asmoke ring exhaust port, a straight section of an exhaust duct, and acurved section of an exhaust duct. It is further anticipated that theheat exchanger has other applications, such as cooling exhaust gassesfrom converting plants, paper manufacturing plants, coal and gas firedelectrical power generation plants, and other exhaust gas generators,where the gasses are cooled for the purpose of capturing one or morecomponents of the gas, where capture is effected by condensation, bycarbon bed absorption, or by filtration.

[0026] A fourth object of the invention is to provide a heat exchangersystem that can be strung together in essentially similar units to coolthe exhaust gasses exiting a metallurgical furnace, such as EAF or BOFfrom 4,000° F.-5,000° F. to 200° F.-350° F.

[0027] A fifth object of the invention is to provide an improved heatexchanger system that is for collecting and cooling slag, where thesinuously winding piping is extruded seamless piping having an elongateridge, where the piping better resists corrosion, erosion, pressure, andthermal stress.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The foregoing and other objects will become more readily apparentby referring to the following detailed description and the appendeddrawings in which:

[0029]FIG. 1 is a partially cut away perspective view illustrating theinvention. The heat exchanger system has at least one panel of sinuouslywinding piping having an inlet and an outlet which are in fluidcommunication with a pair of manifolds. The illustrated panels aremounted on the inside of an exhaust duct.

[0030]FIG. 1a is a perspective view of the invention illustrated inFIG. 1. The exhaust duct is fitted with the heat exchanger system. Theduct is used in the steel making industry to convey and cool exhaustgasses pulled from the steel making furnace. The sinuously windingpiping, which is partially shown in ghost, is made of an aluminum bronzealloy. The duct can also be made of aluminum bronze alloy.

[0031]FIG. 1b is a side view of an elbow exhaust duct connected to astraight exhaust duct, which in turn is connected to an off-gas chamber.

[0032]FIG. 1c is an elevational view of the ducts and the off-gaschamber illustrated in FIG. 1b.

[0033]FIG. 1d is an offset elevational view of a series of coolingexhaust ducts. The series of cooling exhaust ducts are connected to theoff-gas chamber, and the elbow exhaust duct that is connected to a roofof the furnace. The series provides both cooling and ducting of the hotfume gasses and dust being drawn off the furnace.

[0034]FIG. 2 is a planar view of the heat exchanger system configured asa smoke ring, where the smoke ring is comprised of sinuously windingpiping that winds back and forth forming a curved panel that is anellipsoidal ring. The ellipsoidal ring has one inlet and one outlet forthe cooling water. Alternatively, the smoke ring can be configured tohave more than one inlets and outlets.

[0035]FIG. 3 is a cross-sectional view of the invention illustrated inFIG. 2 taken along sectional line 3-3.

[0036]FIG. 4 is a side view of the heat exchanger system configured as asmoke ring illustrated in FIG. 2.

[0037]FIG. 5 is a side view of a panel of sinuously winding piping withan inlet and an outlet. The piping is spaced and linked with brazedlinkages.

[0038]FIG. 6 is a cross-sectional view of the sinuously winding piping,wherein the piping has splines and a base. The base is attached to abase plate that is attached to an interior side of a wall.

[0039]FIG. 7 is a cross-sectional view of the sinuously winding piping,illustrating how the pipes are spaced and linked with connectinglinkages.

[0040]FIG. 8 is a cross-sectional view of a steel making furnace fittedwith numerous components of the heat exchanger system. The system isused in the furnace as well as in the ducts to cool the exhaust gasses.

[0041]FIG. 9 is a cross-sectional view of a heat exchanger system thatutilizes baffles, where the system provides cooling for a duct. Thesystem has a channel created by the baffles, where the baffles directthe flow of the cooling fluid to flow in a serpentine fashion.

[0042]FIG. 10 is a partially cutaway cross-sectional side view of a heatexchanger system that utilizes baffles, where the heat exchanger isfitted on the wall of a steel making furnace. The heat exchanger has analuminum bronze front plate, baffles, and base plate. The front plate isdirectly exposed to the heat, exhaust gasses, and slag produced by thefurnace.

[0043]FIG. 11 is a cross-sectional view of a heat exchanger system thatutilizes spray nozzles, where the heat exchanger is fitted on the wallof a steel making furnace. The heat exchanger has an aluminum bronzefront plate, pipes fitted with nozzles, and base plate. The front plateis directly exposed to the heat, exhaust gasses and slag produced by thesteel making process. The nozzles spray the cooling fluid from the baseplate toward the backside of the front plate. The front plate isdisplaced sufficiently from the nozzles that the cooling fluid isdispersed over a wider area.

[0044]FIG. 12 is a cross-sectional view of a heat exchanger system thatutilizes spray nozzles, where the heat exchanger is an air box. Thealuminum bronze front plate is on the interior of the air box, andpipes, fitted with nozzles, are mounted to the base plate. The nozzlesspray the cooling fluid from pipes secured to the base plate toward thebackside of the front plate. The front plate is displaced sufficientlyfrom the nozzles that the cooling fluid is sprayed in an overlappingpattern. The overlap is sufficient to cover an area. Note, there are twoinlets and two outlets.

DETAILED DESCRIPTION

[0045] As required, detailed embodiments of the present invention aredisclosed herein, however, it is to be understood that the disclosedembodiments are merely exemplary of the invention, which may be embodiedin various forms. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting.

[0046] The heat exchanger system 10 comprises at least one panel ofsinuously winding piping 50 having an inlet 56 and an outlet 58, aninput manifold 84 in fluid communication with the inlet of the at leastone panel, an output manifold 86 in fluid communication with the outletof the at least one panel, and a cooling fluid flowing through thepiping. The heat exchanger system 10 cools hot fume gasses 36 and dustthat is being evacuated from a metallurgical furnace 80 and itssupporting components. The piping is an assemblage of sectional lengthsof connected tubes mounted side-by-side, wherein the connected tubes aresecured to each other with a linkage 82, therein forming the at leastone panel 50. The inventors have empirically determined that a preferredcomposition for fabricating the piping 50 is an aluminum bronze alloy.Aluminum bronze alloys have been found to have a higher than expectedthermal conductivity, resistance to etching by the stream of hot gasses(modulus of elasticity), and good resistance to oxidation. Thus, theoperational life of the heat exchanger is extended. Corrosion anderosion of the heat exchanger and related components is reduced, whenthey are fabricated with aluminum bronze. Table 1 compares the thermalconductivity of aluminum bronze, P22 (Fe˜96%, C˜0.1%, Mn˜0.45%,Cr˜2.65%, Mo˜0.93%) and carbon steel (A106B). Aluminum bronze hasthermal conductivity that is 41% higher than P22 and 30.4% than carbonsteel. The heat exchangers fabricated using aluminum bronze and alloysthereof are more efficient, and have a longer operational life thanfurnace constructed of refractive materials and or other metal alloys.TABLE 1 Property Aluminum Bronze P22 A106B Hardness (HRB) 149 110 106Tensile Strength (KSI) 78 60 60 Elongation (% in 2″) 42 20 19 YieldStrength (KSI) 35 30 35 Thermal Conductivity (W/mK) 32.6 23 25

[0047] It has also been determined that the piping is preferablyextruded, where the piping resists corrosion, erosion, pressure, andthermal stress. Performance is particularly enhanced where the pipinghas an elongate ridge that serves as a fin. The fin can serve to enhancecooling and collect slag. There are no weld lines that can fail, and theextruded seamless piping distributes heat more uniformly, which in turnimproves the overall performance of the heat exchanger system. Thepiping can be curved or bent to match the curvature of a wall to whichit is being attached, if so needed. More typically, the individualsections of piping are secured to each other with an angled linkage suchthat the resulting panel has a curvature that is comparable to thecurvature of the wall.

[0048] The heat exchanger system as illustrated in the drawings employsmanifolds and multiple panels to further enhance the cooling efficiency.The combination assures that cool water is flowing through all thepiping, therein optimizing heat transfer. The sinuously winding pipingoptimizes the surface area. The piping is typically secured usinglinkages and spacers, which enable fume gasses to flow essentiallyaround nearly the entire perimeter of the piping.

[0049] Referring to FIG. 1, the present invention 10 is shown in a fumedexhaust gas duct 44 having a wall 94 with an interior side of the wall93 and an exterior side of the wall 95. The wall 94 is partially cutaway to view the interior of the duct 44. The illustrated duct 44 iselliptical, an engineering construction selected to increase the surfacearea versus a circular duct. The duct is divided into four quadrants,numbered 1-4, as indicated by the abscissas and the ordinate dashedlines. In the instant invention, the heat exchanger utilizes four panelsof sinuously winding piping, each with one inlet 56, and one outlet 58.Each panel is assembled with linkages 52 that serve as spaces andfasteners to secure the pipes 50, and therein establishing the relativeposition of one sectional length of piping with respect to the adjacentsectional lengths of piping. The panels, 1-4, are mounted on the insidewall 93 of the duct 44. Each panel is in fluid communication with aninput manifold 84, and an output manifold 86. The manifolds 84 and 86are mounted to the exterior side 95 of the wall 94, and substantiallyencircle the duct 44. The piping 50 is oriented so as to besubstantially collinear with the wall of the duct 44. The orientation isselected because it is easier to fabricate and creates less pressuredrop over the length of the duct. Both ends of the duct 44 areterminated with a flange 54 that enables the cooling duct to be coupledto another duct. Each duct is substantially a self-contained modularcooling unit. The modularization enables duct fabrication to be to acertain extent generic. Each duct has a cooling capacity, and the ductsare combined in sufficient numbers to achieve the desired cooling. Themodularization is in part due to the fact that the heat exchanger systemis comprised of individually cooled panels having a known coolingcapacity, that when combined determine the cooling capacity of the duct.The cumulative cooling capacity is ultimately, therefore, a function ofthe type, number, and configuration of the panels, and the temperatureand flow rate of the cooling fluid provided by the manifolds. The panelsare largely substantially self-contained, modular components that arealso relatively generic. The fume exhaust duct 44 typically has a pairof mounting supports numbered 62 for attaching the duct to a frame orsupport.

[0050] The external elements of the duct and the heat exchanger systemare illustrated in FIGS. 1a, 1 b, 1 c, and 1 d. The duct 44 can befitted with mounting brackets 60 for attaching the duct to the furnaceroof, to an off-gas chamber (which is sometimes referred to as an airbox 48), or to provide support to the flange 54. Referring to FIG. 1b,the elbow duct 45 is connected to a straight exhaust duct 44, which inturn is connected to an off-gas chamber 48. The elbow shaped duct 45 hasroof brackets 60 for securing the elbow 45 to a furnace roof. A smokering 66 protrudes from the entrance of the elbow duct 66. As can be seenin FIGS. 2-4 and FIG. 8, the smoke ring 66 is the heat exchanger 10having a circular configuration. The elbow duct has an input manifold 84and an output manifold 86. The input manifold 84 is connected to asource of cooling water at 88 and the output manifold 86 is connected toa recycle outlet 90. The elbow duct 45 and the straight duct 44 arecoupled via their respective flanges 54. The straight duct 44 and theoff-gas chamber 48 are coupled via their respective flanges 54. Theoff-gas chamber 48 preferably has a pressure release mechanism on theoff chance that an explosion develops in the furnace. The off-gaschamber 48 also serves as a junction box if additional capacity isrequired at a later date. Referring to FIG. 1c,the partially cooled fumegasses coming off the furnace are diverted 90 degrees to the remainderof the exhaust system 16. The length of the system is sufficient to coolthe exhaust gasses exiting a metallurgical furnace, such as EAF or BOFfrom 4,000° F.-5,000° F. to 200° F.-350° F. As shown in FIG. 1d, thecomplete cooling system outside the furnace is comprised of 8 pairs ofmanifolds after the off-gas chamber 48, plus 2 pairs prior to theoff-gas chamber 48, and a smoke ring. Each pair of manifolds has 4 heatexchanger panels, bringing the total number to 40 panels, plus the smokering panel 66. The smoke ring can be mounted on the roof of the furnace,instead of to a duct, and a discussion of this configuration follows.

[0051] Referring to FIGS. 2-4, which further illustrate the heatexchanger system configured as a smoke ring, where the smoke ring 66 iscomprised of sinuously winding piping that winds back and forth forminga curved panel that is an ellipsoidal ring. The ellipsoidal ring has oneinlet and one outlet for the cooling water. Alternatively, the smokering can be configured to have more than one inlets and outlets. In theembodiment shown, the heat exchanger 10 has three smoke ring brackets 64for mounting the heat exchanger to a domed furnace roof. The piping 50,as shown in FIG. 3, is more compressed on the right than on the left,and the bracket 64 on the left is lower on the left than on the right.The compression and the different placement of the bracket compensatesfor the pitch of the roof, which result in a profile that issubstantially vertical. The linkages 82 establish not only the curvatureof the panel of sinuously winding piping 50, but also the profile.

[0052] Referring to FIG. 8, the illustrative furnace is shown as an EAFtype furnace 80. It is to be understood that the EAF disclosed is forexplanation only and that the invention can be readily applied in BOFtype furnaces and the like. In FIG. 8, an EAF 80 includes a furnaceshell 12, a plurality of electrodes 14, an exhaust system 16, a workingplatform 18, a rocker tilting mechanism 20, a tilt cylinder 22, and anoff gas chamber b. The furnace shell 12 is movably disposed upon therocker tilt 20 or other tilting mechanism. Further, the rocker tilt 20is powered by tilt cylinder 22. The rocker tilt 20 is further securedupon the working platform 18.

[0053] The furnace shell 12 is comprised of a dished hearth 24, agenerally cylindrical side wall 26, a spout 28, a spout door 30, and ageneral cylindrical circular roof 32. The spout 28 and spout door 30 arelocated on one side of the cylindrical side wall 26. In the openposition, the spout 28 allows intruding air 34 to enter the hearth 24and partially burn gasses 36 produced from smelting. The hearth 24 isformed of suitable refractory material which is known in the art. At oneend of the hearth 24 is a pouring box having a tap means 38 at its lowerend. During a melting operation, the tap means 38 is closed by arefractory plug, or a slidable gate. Thereafter, the furnace shell 12 istilted, the tap means 38 is unplugged, or open and molten metal ispoured into a teeming ladle, tundish, or other device, as desired.

[0054] The inside wall 26 of the furnace shell 12 is fitted with watercooled panels 40 of sinuously winding piping 50. The panels, in effectserve as an interior wall in the furnace 80. The manifolds, which supplycool water and a return, are in fluid communication with the panels 40.Typically, the manifolds are positioned peripherally in a fashionsimilar to the illustrated exhaust ducts 44. The cross-section of themanifolds are shown outside the furnace shell 12 in FIG. 8. The heatexchanger system 10 produces a more efficient operation and prolongs theoperation life of the EAF furnace 10. In a preferred embodiment, thepanels 40 are assembled such that the sinuously winding piping has agenerally horizontal orientation, comparable to the smoke ringillustrated in FIGS. 2-4. The piping 50 can be linked with a linkage 82,as shown in FIG. 7, or can have a base 92 that is mounted to the wall94. Typically, with the latter configuration the piping has elongateridges 96 for collecting slag and adding additional surface area to thepiping. Alternatively, the panels 40 are mounted such that the sinuouslywinding piping 50 has a generally vertical orientation as shown in FIG.5. The upper ends of the panels 40 define a circular rim at the uppermargin of the side wall 26 portion of the furnace 80.

[0055] The heat exchanger system 10 can be fitted to the roof 32 of thefurnace 80, wherein the water cooled panels 40 have a curvature thatsubstantially follows the domed contour of the roof 32. The heatexchanger system 10, therein, is deployed on the inside of side wall 26of the furnace 80, the roof 32 and the entrance of the exhaust system16, as well as the throughout the exhaust system 16. Cumulatively, theheat exchanger system protects the furnace and cools the hot wastegasses 36 as they are ducted to a bag house or other filtering and airtreatment facilities, where dust is collected and the gasses are ventedto the atmosphere.

[0056] In operation, hot waste gasses 36, dust and fumes are removedfrom the hearth 24 through vent 46 in the furnace shell 12. The vent 46communicates with the exhaust system 16 comprised of the fume ducts 44,as shown in FIGS. 1 and 1a-1 d.

[0057] Referring to FIG. 5, the panel 40 has multiple axially arrangedpipes 50. U-shaped elbows 53 connect adjacent sectional lengths ofpiping or pipes 50 together to form a continuous piping system. Linkages82 that additionally serve as spacers are between adjacent pipes 50, andthey provide structural integrity of the panel 40 and are determinativeof curvature to the panel 40.

[0058]FIG. 7 is a cross-sectional view of the panel embodiment of FIG.5. A variation is illustrated in FIG. 6, wherein the pipes 50 have atubular cross-section, a base 92, an elongate ridge 96, and a base plate93. The base plate 93 is attached to the furnace wall 26, or to thefurnace roof 32. The combination of the piping and, optionally, the baseplate forms panel 40, which creates an interior wall of the furnace. Thepanels 40 cool the wall 26 of the furnace above the hearth in an EAF orthe hood and fume ducts of a BOF.

[0059] The panels are water cooled, and are comprised of an aluminumbronze alloy that is custom melted and processed into a seamless pipe50. The cooling ducts 44 are incorporated into the exhaust system 16.Moreover, the piping 50 is formed into the cooling panels 40 and placedthroughout the roof 32 and ducts 44. The aluminum bronze alloypreferably has a nominal composition of: 6.5% Al, 2.5% Fe, 0.25% Sn,0.5% max Other, and Cu equaling the balance. However, it will beappreciated that the composition may vary, so that the Al content is atleast 5% and no more than 11% with the respective remainder comprisingthe bronze compound.

[0060] The use of the aluminum bronze alloy provides enhanced mechanicaland physical properties over prior art devices (i.e., carbon orstainless steel cooling systems) in that the alloy provides superiorthermal conductivity, hardness, and modulus of elasticity for thepurposes of steel making in a furnace. By employing these enhancements,the operational life of the furnace is directly increased.

[0061] In addition to the superior heat transfer characteristics, theelongation capabilities of the alloy is greater than that of steel orstainless steel, thereby allowing the piping and duct work 44 to expandand contract without cracking. Further, the surface hardness is superiorover the prior art in that it reduces the effects of erosion from thesand blasting effect of off-gas debris.

[0062] The process of forming the piping is preferably extrusion,however, one skilled in the art will appreciate that other formingtechniques may be employed which yield the same result, i.e., a seamlesscomponent. During extrusion, the aluminum bronze alloy is hot worked,thereby resulting in a compact grain structure, which possesses improvedphysical properties.

[0063] In the pipes shown in FIG. 6, the elongate ridge 96 is a splinethat is especially suitable for collecting slag. The mass on each sideof the centerline of the tubular section is equivalent, so that the massof the elongate ridge 96 is approximately equal to the mass of the base92. By balancing the mass and employing extruded aluminum bronze alloys,the resulting pipe is substantially free of stress risers. The disclosedpipe has improved stress characteristics, and heat exchange panelsfabricated with these pipes are less subject to damage caused bydramatic temperature changes, for instance, during the cycling of thefurnace.

[0064] The composition of the heat exchanger system differs from theprior art in that piping and plates in the prior art were composed ofcarbon-steel or stainless steel, as opposed to the disclosed compositionof aluminum bronze alloy. The composition of the aluminum bronze alloyis not as prone to acid attack. Furthermore, applicants' have determinedthat aluminum bronze has a higher heat transfer rate than bothcarbon-steel or stainless steel, and that the alloy possesses thecapability to expand and contract without cracking. Finally, the surfacehardness of the alloy is greater than that of either steel, therebyreducing the effects of eroding the surface from the sand blastingeffects of the exhaust gas moving through the duct/cooling system.

Alternative Embodiment

[0065] A similar flow of the cooling fluid through the heat exchangersystem is achieved through the use of a sinuously winding channel. Thechannel 122 is formed by interspacing baffles 124 between a front plate120 and the base plate 93. FIG. 9 illustrates an embodiment of the heatexchanger system 10 using baffles. In the illustrated embodiment, theheat exchanger system 10 is a duct 45, where the front plate 120 is onthe interior of the duct 45. In the illustrated embodiment, the baseplate 93 also functions as the exterior wall of the duct 45. The ducthas flanges 54 for coupling one duct to another duct, or coupling to anair box 48, or coupling to the roof 32 of the furnace 80. In theillustrated embodiment the cooling fluid flows in and out of the planeof the paper. As illustrated, there is only one panel 41, and it is influid communication with an input manifold (not shown) and an outputmanifold (not shown). The manifolds are mounted to the exterior side ofthe base plate 93.

[0066]FIG. 10 illustrates the heat exchanger system 10 configured as aninterior furnace wall 47, which is cooling panel 41. The interiorfurnace wall 47 is fabricated to follow the contour of the wall 26 ofthe furnace shell 12. The panel 41 has baffles 124 mounted between thefront plate 120 and the base plate 93. The system has an inlet 56 and anoutlet 58 for the cooling fluid. The manifolds, which supply cool waterand a return, are in fluid communication with the panel 41. Althoughonly one panel is shown, the application could be configured to havemultiple panels. The front plate 120 and the baffles 124 have analuminum bronze alloy composition. The baffles are welded to the frontplate along longitudinal edge 126. The base plate is attached to theopposing longitudinal edge, therein forming the channel 122. The channel122 can be seen on the left hand side comer of FIG. 10. Note, the flowof the cooling fluid is sinuously winding in a serpentine fashion, verysimilar to the flow through the assemblage of pipes mountedside-by-side, as shown in FIG. 5. The manifolds are not shown inembodiment 45 or 47, but are positioned peripherally, as previouslyillustrated in FIG. 2.

[0067] Referring to FIG. 11, which illustrates an interior furnace wall49 cooled with a panel 43 having a plurality of spray nozzles 125. Theheat exchanger has an aluminum bronze front plate 120, pipes 50 fittedwith nozzles 125 and a base plate 93. The front plate 120 is directlyexposed to the heat, exhaust gasses, and slag produced by the steelmaking process. The nozzles 50 spray the cooling fluid from the baseplate toward the backside of the front plate 120.

[0068] Referring to FIG. 12, which is a cross-sectional view of an airbox 48 that is cooled using a heat exchanger system that utilizes spraynozzles 125. The four aluminum bronze front plates 120 define theinterior of the air box 48. The plurality of nozzles 125 on pipe 50,direct a pattern spray of cooling fluid to the back side of the frontplate 120. The base plate 93 serves as a mount for the pipes 50 as wellas an exterior wall for the air box 48. The front plate 120 is displacedsufficiently from the plurality of nozzles that the cooling fluid issprayed in an overlapping pattern. The overlap is sufficient to cover anarea, which reduces the number of serpentine windings necessary to coolthe front plate. In the illustrated embodiment shown in FIG. 12 there isan assemblage of only two pipes shown, each with an inlet 56 and anoutlet 58. Not shown could be many more pipes with nozzles. ReviewingFIG. 11, the pipes are connected with U shaped elbows 53, and similarconnections can be used in the air box 48. As illustrated, there is onlyone panel 43 having at least one inlet and outlet.

[0069] Although particular embodiments of the invention have beendescribed in detail, it will be understood that the invention is notlimited correspondingly in scope, but includes all changes andmodifications coming within the spirit and terms of the claims appendedhereto. It should be obvious that the heat exchanger system, whetherutilizing sinuously winding piping, baffles or spray nozzles and platescan be employed in extremely harsh environments to cool gasses andcondense many vaporized materials.

Summary of the Achievement of the Objects of the Invention

[0070] From the foregoing, it is readily apparent that we have inventedan improved heat exchanger system constructed of aluminum bronze alloys,where aluminum bronze alloys have been found to have a higher thanexpected thermal conductivity, resistance to etching by the stream ofhot gasses, and good resistance to oxidation. Furthermore, we haveprovided a heat exchanger system wherein the operational life of theheat exchanger is extended, as corrosion, and erosion of the heatexchanger, and related components is reduced when they are fabricatedwith aluminum bronze alloy.

[0071] Additionally provided is a heat exchanger system that isadaptable for cooling exhaust gasses emanating from a steel makingfurnace, wherein the heat exchanger system can be fitted to the walls ofthe furnace, a furnace roof, a smoke ring exhaust port, a straightsection of an exhaust duct, and a curved section of an exhaust duct. Theheat exchanger system cools the exhaust gasses exiting a metallurgicalfurnace such as EAF or BOF from 4,000° F.-5,0000° F. to 200° F.-350° F.

[0072] The invention provides a heat exchanger system that can beadapted for collecting and cooling slag, where the sinuously windingpiping is extruded seamless piping having an elongate ridge, and thepiping resists corrosion, erosion, pressure, and thermal stress.

[0073] Also provided is a heat exchanger that has other applications,such as cooling exhaust gasses from converting plants, papermanufacturing plants, coal and gas fired electrical power generationplants, and other exhaust gas generators, where the gasses are cooledfor the purpose of capturing one or more components of the gas, wherecapture is effected by condensation, by carbon bed absorption, or byfiltration.

[0074] It is to be understood that the foregoing description andspecific embodiments are merely illustrative of the best mode of theinvention and the principles thereof, and that various modifications andadditions may be made to the apparatus by those skilled in the art,without departing from the spirit and scope of this invention.

What is claimed is:
 1. A heat exchanger system, said system comprising:at least one panel of sinuously winding piping having an inlet and anoutlet; an input manifold in fluid communication with the inlet of theat least one panel; an output manifold in fluid communication with theoutlet of the at least one panel; a cooling fluid flowing through thepiping; a stream of hot gasses flowing over the piping; wherein thesinuously winding piping is substantially an assemblage of sectionallengths of connected tubes mounted side-by-side; and wherein theconnected tubes are secured to each other with a linkage therein formingthe at least one panel.
 2. The heat exchanger system, according to claim1, wherein the at least one panel is mounted to an interior side of awall, and is in fluid communication with the output and the inputmanifolds that are on an exterior side of the wall.
 3. The heatexchanger system, according to claim 2, wherein the wall has curvature,as for instance does the wall of a steel making furnace, a furnace roof,a smoke ring exhaust port, a straight section of an exhaust duct, and acurved section of an exhaust duct.
 4. The heat exchanger system,according to claim 3, wherein the connected tubes are secured to eachother with an angled linkage such that the resulting panel has acurvature that is comparable to the curvature of the wall.
 5. The heatexchanger system, according to claim 4, wherein a plurality of the atleast one panels are mounted around the interior side of the exhaustduct, wherein the plurality are individually supplied the cooling liquidfrom the output manifold which encircles the exterior side of theexhaust duct; and wherein each panel returns the cooling liquid to theoutput manifold which encircles the exterior side of the exhaust duct.6. The heat exchanger system, according to claim 4, wherein a pluralityof the at least one panel are mounted around the interior side of thefurnace roof, wherein each panel is individually supplied the coolingliquid from the output manifold that is on an exterior side of thefurnace roof; and wherein each panel returns the cooling liquid to theoutput manifold which is on the exterior side of the furnace roof. 7.The heat exchanger system, according to claim 4, wherein a plurality ofthe at least one panels are mounted around the interior side of thefurnace wall, wherein each panel is individually supplied the coolingliquid from the output manifold which encircles the exterior side of thefurnace wall; and wherein each panel individually returns the coolingliquid to the output manifold which encircles the exterior side of thefurnace wall.
 8. The heat exchanger system, according to claim 4,wherein a plurality of the at least one panel are mounted around theinterior side of the smoke ring exhaust port, wherein each panel isindividually supplied the cooling liquid from the output manifold whichencircles the exterior side of the smoke ring exhaust port; and whereineach panel returns the cooling liquid to the output manifold whichencircles the exterior side of the smoke ring exhaust port.
 9. The heatexchanger system, according to claim 5, wherein the connected tubes aremounted lengthwise in the exhaust ducts.
 10. The heat exchanger system,according to claim 3, wherein there are a sufficient number of exhaustducts strung together that the total number of panels in the exhaustducts and the smoke ring exhaust port lowers the temperature of thestream of hot gasses pulled from the furnace from about 4,000° F.-5,000°F. to about 200° F.-350° F.
 11. The heat exchanger system, according toclaim 1, wherein the connected tubes have a spline.
 12. The heatexchanger system, according to claim 1, wherein the spline tubes have anelongate ridge to enhance surface area, collect slag, and reduce stressrisers.
 13. The heat exchanger system, according to claim 1, wherein thecooling fluid flowing through the piping is water.
 14. The heatexchanger system, according to claim 1, wherein the at least one panelof sinuously winding piping is comprised of an aluminum bronze alloy.15. The heat exchanger system, according to claim 14, wherein said alloycomprises at least 89% copper and no more than 95% copper.
 16. The heatexchanger system, according to claim 14, wherein the aluminum bronzealloy comprises Cu, Al, Sn, and Fe.
 17. The heat exchanger system,according to claim 10, wherein the shape and size of the exhaust ductare sized to attain a desired surface area, wherein the exhaust duct hasa known cooling capacity.
 18. The heat exchanger system, according toclaim 10, wherein the sinuously winding piping is comprised of analuminum bronze alloy.
 19. A heat exchanger system, said systemcomprising: at least one panel of sinuously winding piping having aninlet and an outlet, wherein the at least one panel is affixed to a baseplate; an input manifold in fluid communication with the inlet of the atleast one panel; an output manifold in fluid communication with theoutlet of the at least one panel; a cooling fluid flowing through thepiping; a stream of hot gasses flowing over the piping; wherein thesinuously winding piping is substantially an assemblage of sectionallengths of connected tubes mounted side-by-side; and wherein theconnected tubes are secured to each other and to the base plate with alinkage therein forming the at least one panel.
 20. The heat exchangersystem, according to claim 19, wherein the at least one panel is mountedto an interior side of a wall, and is in fluid communication with theoutput and the input manifolds that are on an exterior side of the wall.21. The heat exchanger system, according to claim 20, wherein the wallhas curvature, as for instance does the wall of a steel making furnace,a furnace roof, a smoke ring exhaust port, a straight section of anexhaust duct, and a curved section of an exhaust duct.
 22. The heatexchanger system, according to claim 21, wherein the base plate iscurved, and the connected tubes are secured to each other with an angledlinkage such that the resulting panel has a curvature that is comparableto the curvature of the wall.
 23. The heat exchanger system, accordingto claim 22, wherein a plurality of the at least one panel are mountedaround the interior side of the exhaust duct, wherein each panel isindividually supplied the cooling liquid from the output manifold whichencircles the exterior side of the exhaust duct; and wherein each panelreturns the cooling liquid to the output manifold which encircles theexterior side of the exhaust duct.
 24. The heat exchanger system,according to claim 22, wherein a plurality of the at least one panel aremounted around the interior side of the furnace roof, wherein each panelis individually supplied the cooling liquid from the output manifoldwhich is on an exterior side of the furnace roof; and wherein each panelreturns the cooling liquid to the output manifold which is on theexterior side of the furnace roof.
 25. The heat exchanger system,according to claim 22, wherein a plurality of the at least one panelsare mounted around the interior side of the furnace wall, wherein eachpanel is individually supplied the cooling liquid from the outputmanifold which encircles the exterior side of the furnace wall; andwherein each panel individually returns the cooling liquid to the outputmanifold which encircles the exterior side of the furnace wall.
 26. Theheat exchanger system, according to claim 22, wherein a plurality of theat least one panels are mounted around the interior side of the smokering exhaust port, wherein the each panel is individually supplied thecooling liquid from the output manifold which encircles the exteriorside of the smoke ring exhaust port; and wherein each panel returns thecooling liquid to the output manifold which encircles the exterior sideof the smoke ring exhaust port.
 27. The heat exchanger system, accordingto claim 23, wherein the connected tubes are mounted lengthwise in theexhaust ducts.
 28. The heat exchanger system, according to claim 21,wherein there are a sufficient number of exhaust ducts strung togetherthat the total number of panels in the exhaust ducts and the smoke ringexhaust port lowers the temperature of the stream of hot gasses pulledfrom the furnace from about 4,000° F.-5,000° F. to about 200° F.-350° F.29. The heat exchanger system, according to claim 19, wherein theconnected tubes have a spline.
 30. The heat exchanger system, accordingto claim 19, wherein the spline tubes have an elongate ridge to enhancesurface area, collect slag and reduce stress risers.
 31. The heatexchanger system, according to claim 19, wherein the cooling fluidflowing through the piping is water.
 32. The heat exchanger system,according to claim 19, wherein the at least one panel of sinuouslywinding piping is comprised of an aluminum bronze alloy.
 33. The heatexchanger system, according to claim 32, wherein said alloy comprises atleast 89% copper and no more than 95% copper.
 34. The heat exchangersystem, according to claim 32, wherein the aluminum bronze alloycomprises Cu, Al, Sn, and Fe.
 35. The heat exchanger system, accordingto claim 27, wherein the shape and size of the exhaust duct are sized toattain a desired surface area, wherein the exhaust duct has a knowncooling capacity.
 36. The heat exchanger system, according to claim 27,wherein the sinuously winding piping is comprised of an aluminum bronzealloy.
 37. The heat exchanger system, according to claim 32, wherein thealuminum bronze alloy tubes are formed by extruding the pipe, whereinsaid extruded aluminum bronze pipe has superior properties for bending.38. A heat exchanger system, said system comprising: at least one panelof a sinuously winding channel through a front plate and a base plate,the at least one panel having an inlet and an outlet; an input manifoldin fluid communication with the inlet of the at least one panel; anoutput manifold in fluid communication with the outlet of the at leastone panel; a cooling fluid flowing through the channel; a stream of hotgasses flowing over the front plate; and wherein the sinuously windingchannel is substantially an assemblage of baffles mounted between thefront plate and the base plate that route the cooling fluid.
 39. Theheat exchanger system, according to claim 38, wherein the assemblage ofbaffles are fabricated such that a longitudinal edge of a baffle isperpendicularly mounted to a backside of the front plate, approximatelyequidistant from an adjacent baffle, and covered with the base plate,where the resulting channel emulates a fabricated tube.
 40. The heatexchanger system, according to claim 39, wherein the at least one panelis mounted to an interior side of a wall, and is in fluid communicationwith the output and the input manifolds that are on an exterior side ofthe wall.
 41. The heat exchanger system, according to claim 40, whereinthe wall has curvature, as for instance does the wall of a steel makingfurnace, a furnace roof, a smoke ring exhaust port, a straight sectionof an exhaust duct, and a curved section of an exhaust duct, or the wallis straight as is commonly employed for air boxes.
 42. The heatexchanger system, according to claim 40, wherein a plurality of the atleast one panel are mounted around the interior side of the exhaustduct, wherein each panel is individually supplied the cooling liquidfrom the output manifold which encircles the exterior side of theexhaust duct; and wherein each panel returns the cooling liquid to theoutput manifold which encircles the exterior side of the exhaust duct.43. The heat exchanger system, according to claim 40, wherein aplurality of the at least one panel are mounted around the interior sideof the furnace roof, wherein each panel is individually supplied thecooling liquid from the output manifold which is on the exterior side ofthe furnace roof, and wherein each panel returns the cooling liquid tothe output manifold which is on the exterior side of the furnace roof.44. The heat exchanger system, according to claim 40, wherein aplurality of the at least one panel are mounted around the interior sideof the furnace wall, wherein each panel is individually supplied thecooling liquid from the output manifold which encircles the exteriorside of the furnace wall; and wherein each panel individually returnsthe cooling liquid to the output manifold which encircles the exteriorside of the furnace wall.
 45. The heat exchanger system, according toclaim 41, wherein a plurality of the at least one panel are mountedaround the interior side of the smoke ring exhaust port, wherein eachpanel is individually supplied the cooling liquid from the outputmanifold which encircles the exterior side of the smoke ring exhaustport; and wherein each panel returns the cooling liquid to the outputmanifold which encircles the exterior side of the smoke ring exhaustport.
 46. The heat exchanger system, according to claim 38, whereinthere are a sufficient number of exhaust ducts strung together that thetotal number of panels in the exhaust ducts and the smoke ring exhaustport lowers the temperature of the stream of hot gasses pulled from thefurnace from about 4,000° F.-5,000° F. to about 200° F.-350° F.
 47. Theheat exchanger system, according to claim 38, wherein the front plate iscomprised of an aluminum bronze alloy.
 48. The heat exchanger system,according to claim 47, wherein the assemblage of baffles is comprised ofan aluminum bronze alloy.
 49. The heat exchanger system, according toclaim 48, wherein said alloy comprises at least 89% copper and no morethan 95% copper.
 50. The heat exchanger system, according to claim 48,wherein the aluminum bronze alloy is comprised of Cu, Al, Sn, and Fe.51. The heat exchanger system, according to claim 38, wherein the heatexchanger system is suitable for cooling exhaust gasses generated byiron and steel manufacturing plants, converters, paper manufacturingplants, coal and gas fired electrical power generation plants, and otherplants that generate exhaust gasses.
 52. The heat exchanger system,according to claim 38, wherein the heat exchanger system is suitable foruse on iron and steel manufacturing furnace walls.
 53. The heatexchanger system, according to claim 1, wherein the heat exchangersystem is suitable for cooling exhaust gasses generated by iron andsteel manufacturing plants, converters, paper manufacturing plants, coaland gas fired electrical power generation plants, and other plants thatgenerate exhaust gasses.
 54. The heat exchanger system, according toclaim 1, wherein the heat exchanger system is suitable for the furnacewalls of iron and steel manufacturing furnaces.
 55. The heat exchangersystem, according to claim 19, wherein the heat exchanger system issuitable for cooling exhaust gasses generated by iron and steelmanufacturing plants, converters, paper manufacturing plants, coal andgas fired electrical power generation plants, and other plants thatgenerate exhaust gasses.
 56. The heat exchanger system, according toclaim 19, wherein the heat exchanger system is suitable for the furnacewalls of iron and steel manufacturing furnaces.
 57. A heat exchangersystem, said system comprising: at least one panel of piping having aplurality of spray nozzles, said piping mounted on a base plate offsetfrom a front plate, wherein the at least one panel has an inlet and anoutlet; an input manifold in fluid communication with the inlet of theat least one panel; an output manifold in fluid communication with theoutlet of the at least one panel; a cooling fluid flowing through thepiping and being sprayed through the nozzles; a stream of hot gassesflowing over the front plate; wherein the spray nozzles direct anddisperse the cooling fluid onto the backside of the front plate, therebyproviding heat transfer from the front plate to the cooling fluid; andwherein the front plate is comprised of an aluminum bronze alloy. 58.The heat exchanger system, according to claim 57, wherein the at leastone panel is mounted to an interior side of a wall, and is in fluidcommunication with the output and the input manifolds that are on anexterior side of the wall.
 59. The heat exchanger system, according toclaim 57, wherein the wall has curvature, as for instance does the wallof a steel making furnace, a furnace roof, a smoke ring exhaust port, astraight section of an exhaust duct, and a curved section of an exhaustduct, or the wall is straight as is commonly employed for air boxes. 60.The heat exchanger system, according to claim 57, wherein a plurality ofthe at least one panel are mounted around the interior side of theexhaust duct, wherein each panel is individually supplied the coolingliquid from the output manifold which encircles the exterior side of theexhaust duct; and wherein each panel returns the cooling liquid to theoutput manifold which encircles the exterior side of the exhaust duct.61. The heat exchanger system, according to claim 57, wherein the outletis near the bottom of the at least one panel such that drainage isalways toward the bottom so as to prevent a buildup of cooling fluidfrom obstructing the plurality of nozzles.
 62. The heat exchangersystem, according to claim 57, wherein a plurality of the at least onepanel are mounted around the interior side of the furnace roof, whereineach panel is individually supplied the cooling liquid from the outputmanifold which is on an exterior side of the furnace roof; and whereineach panel returns the cooling liquid to the output manifold which isdistributed over the exterior side of the furnace roof.
 63. The heatexchanger system, according to claim 57, wherein a plurality of the atleast one panel are mounted around the interior side of the furnacewall, wherein each panel is individually supplied the cooling liquidfrom the output manifold which encircles the exterior side of thefurnace wall; and wherein each panel individually returns the coolingliquid to the output manifold which encircles the exterior side of thefurnace wall.
 64. The heat exchanger system, according to claim 59,wherein a plurality of the at least one panel are mounted around theinterior side of the smoke ring exhaust port, wherein each panel isindividually supplied the cooling liquid from the output manifold whichencircles the exterior side of the smoke ring exhaust port; and whereineach panel returns the cooling liquid to the output manifold whichencircles the exterior side of the smoke ring exhaust port.
 65. The heatexchanger system, according to claim 57, wherein there are a sufficientnumber of exhaust ducts strung together that the total number of panelsin the exhaust ducts and the smoke ring exhaust port lowers thetemperature of the stream of hot gasses pulled from the furnace fromabout 4,000° F.-5,000° F. to about 200° F.-350° F.
 66. The heatexchanger system, according to claim 57, wherein the aluminum bronzealloy comprises Cu, Al, Sn, and Fe.
 67. The heat exchanger system,according to claim 38, wherein the heat exchanger system is suitable forcooling exhaust gasses generated iron and steel manufacturing plants,converting plants, paper manufacturing plants, coal and gas firedelectrical power generation plants, and other plants that generateexhaust gasses.
 68. The heat exchanger system, according to claim 57,wherein said aluminum bronze alloy is extruded.